Water-Resources Investigations in Wisconsin

The statewide average precipitation of 33.37 inches for the 1996 water year was 105 percent of the normal annual precipitation of 31.79 inches for water years 1961-90. Average precipitation values ranged from 77 percent of normal at Trempealeau Dam 6 weather station in west central Wisconsin to 151 percent of normal at Oconto 4 W weather station in northeast Wisconsin (State Climatologist Office, Geological and Natural History Survey, written commun., 1997).

Runoff was variable for rivers throughout the State ranging from 64 percent in southwest Wisconsin to 212 percent in east central Wisconsin. Runoff was lowest (64 percent of the average annual runoff from 1935-96) for the Platte River near Rockville and highest (212 percent of the average annual runoff from 1949-69, 1988-96) for the South Branch Rock River at Waupun. Departures of runoff in the 1996 water year as a percent of long-term average runoff in the State are shown in Figure 4. EXPLANATION